In a typical computer network, computer systems are coupled in the computer network in a manner that enables the computer systems to access data from a variety of sources. Data accessed by such network coupled computer systems can be taken from internal and external sources of information. Unfortunately, often times the data that is accessed can include malicious software that is designed to infiltrate and/or damage the computer systems. Such malicious software is called “malware.”
Malware as used herein can include but is not limited to computer viruses, worms, trojan horses, spyware and some adware. For reasons that are apparent, malware operates without the informed consent of computer system owners. Moreover, malware can be designed to frustrate computer system software (or hardware), such as antivirus programs, that can be installed on the computer system as a defense against active malware.
Malware has become a major problem for computer users all over the world and is increasingly used by criminals as a means to conduct unlawful business enterprises. When a computer has been infected with malware for such purposes, the computer user is generally unaware that their machine has been infected and do not know that their otherwise legitimate status has been hijacked. Moreover, their machine can operate, unbeknownst to the computer user, as a base for the spread of malware or the conduct of illegal activities. The effectiveness of such malfeasance makes the distribution of malware an especially troublesome and problematic part of online communication today. For example, in Windows Live Hotmail, it is estimated that 0.001% of all email contains known malware and that only 1% of all email containing executable attachments is considered to be legitimate or “good”.
Data file attachments to electronic communications such as email provide a particularly useful platform for the distribution of malware. Individuals who receive electronic communications (e.g., email, links to data files) that have a data file attachment, are particularly vulnerable as they generally do not possess sufficient information about the data file attachment to determine if they can safely open it. It should be appreciated that this is true even if the data file attachment is from a trusted sender because the trusted sender's computer may be compromised by malware unbeknownst to the sender. Conventional, antivirus programs do not address the information deficit that renders computer system users vulnerable to malware infection derived from such data file attachments. Accordingly, conventional antivirus programs are inadequate to prevent infection from malware that can be associated with data files that are attached to electronic communications.